Slit unit for optical instruments



Nov. 19, 1935. ssm 2,021,232

SLIT UNIT FOR OPTICAL INSTRUMENTS Filed March 31, 1933 GUSTAVE FASSIN INVENTOR ATTORNEY Patented Nov. 19, 1935 UNITED STATES PATENT OF FlCE SLIT UNIT FOR OPTICAL INSTRUMENTS Application March 31,

7 Claims.

This invention relates to optical instruments and more particularly it has reference to a slit unit which is adapted for use in various types of optical instruments such as spectrometers, spectrographs, monochromators and the like.

One of the objects of my invention is to provide an improved slit unit which will be sensitive and accurate in operation yet relatively simple and rugged in structure. Other objects are to provide a slit unit having swingably mounted jaws and cam means for adjusting same; relatively few moving parts which can be readily assembled or taken apart and slit adjusting means charac terized by freedom from back-lash and lost motion. These and other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully described and pointed out in the appended claims.

Referring to the drawing:

Fig. 1 is a perspective view of a slit unit embodying my invention. Fig. 2 is a vertical sectional view taken through the plane of the slit.

Fig. 3 is a vertical sectional view taken trans- I versely of the slit axis.

Fig. 4 is a plan view of the underside of the two jaw plates.

A preferred embodiment of my invention is disclosed in the drawing wherein I0 indicates a base provided with a central opening I I. Formed integrally with base I0 are the two spaced brackets I2 and I2 carrying the fixed pins I3 and I3, respectively. Mounted between the brackets are the two similar jaw carriers I4 and I5, each having the two spaced extensions I4 and I5, respectively. Each of the two extensions I4 and the two extensions I5 is provided, on its edge, with a substantially right angled notch I6. Springs I 1 seated in notches I8 on each of the extensions I4 and I5 urge the jaw carriers I4 and I5 together so that the notches I6 of the adjacent pairs of extensions I4 and I5 are held, respectively, against the fixed pins I3 and I3. Hence the two jaw carriers I4 and I5 are mounted to swing about the axis of the aligned pins I3 and I3.

The springs I! normally urge the jaw carriers together but they may be moved apart by means of a screw I9 which is threadedly mounted in bracket I2. The end of the screw I9 has a tapered portion I9 which contacts on opposite sides with the adjacent edges 20 and 2I on the extensions I4 and I5. As the screw I8 is turned in one direction, by means of knob 22, the ta- 1933, Serial No. 663,808

percd end I9 advances and exerts a camming action on the edges 20 and 2| so that the jaw car- Iiers I4 and I5 are moved apart from each other against the action of springs IT to provide a slit 21. tion will. of course, retract the tapered end I9 and permit the jaw carriers to move towards each other under the action of springs I]. On theunder side of jaw carriers I4 and I5 the jaw plates 23 and 24 are respectively mounted by 10 means of screws 25 thereby permitting the plates to be adjusted so that their two adjacent edges are parallel.

From the foregoing. it will be apparent that I am able to attain the objects of my invention and 15 provide an improved slit unit which will be sensitive and accurate in operation, yet relatively simple and rugged in structure. The slit 21 is, of course. positioned opposite'opening II so that the unit can be placed in an optical system. The 20 slit 2! can be readily adjusted as to size by merely turning knob 22. Such adjustments are made without any lost motion or back-lash .thereby rendering the slit highly sensitive and accurate. The jaw carriers can be easily and Z5 quickly removed by merely removing springs. Since there are only three moving parts, namely, the two jaw carriers and the screw, the unit is relatively simple in structure. Although I have shown my invention as embodied in a bi-lateral slit, having two jaws moving equally in opposite directions, it is obvious that my invention can be equally well applied to a slit unit having one fixed jaw and one movable jaw. The jaw carrier I4, for example, could be rigidly secured so that the slit 2! could be varied as to width by means of screw I9 which would act to move the jaw carrier I5. Other modifications can obviously be made without departing from the spirit of my invention.

I claim:

1. A slit unit for optical instruments comprising a base, a pair of jaws mounted on said base to turn about a common axis substantially parallel to the edges of said jaws, yieldable means normally urging said jaws together and means for moving said jaws about said axis and holding them in adjusted position.

2. A slit unit for optical instruments comprising a base, a pair of jaws mounted on said base to swing about an axis substantially parallel to the edges of said jaws and move to and from each other, yieldable means normally urging said jaws together and cam means for moving said jaws apart.

Turning the screw I9 in an opposite direc- 5 3. A slit unit for optical instruments comprising a base, a pair of carriers movably mounted on said base to swing about a common axis, a jaw on each carrier, yieldable means for normally urging said jaws together and a screw mounted on said base, said screw having a tapered end which contacts with said carriers whereby the distance between said jaws may be varied.

4. A slit unit for optical instruments comprising a base having two spaced brackets, a stub shaft on each of said brackets, a jaw carrier having spaced extensions each of which is provided with a notch, said carrier being positioned between said brackets with the notches engaging the respective stub shafts whereby said carrier is swing-. ably mounted, a first jaw carried by said base, a second jaw mounted on said carrier and adapted to be moved to and from said first jaw and means for moving said second jaw.

5. A slit unit for optical instruments comprising a base having two spaced brackets, a stub shaft on each of said brackets, a pair of jaw carriers, each of said carriers having two extensions, each extension having a notch on its edge, said carriers being positioned between said brackscrew threadedly mounted in one of said brackets, 5

said screw having a tapered end which contacts with said carriers whereby said jaw plates may be adjustably separated.

6. A slit unit for optical instruments comprising a base, a pair of jaws mounted on said base, cylindrical shaft means carried by said base, notch means on one jaw for hearing engagement with said shaft means, yieldable means for urging said one jaw toward the other jaw, and means for adjustably moving said one jaw away from the other jaw.

7. A slit unit for optical instruments comprising a base, a pair of jaws mounted on said base, cylindrical shaft means parallel to the edges of said jaws carried by said base, notch means on one jaw for bearing engagement with said shaft means, yieldable means for urging said one jaw toward the other jaw, and means for adjustably moving said one jaw away from the other jaw.

GUSTAVE mssm. 

